Lift-type non-lubricated plug valves are well-known in the art and are used in a variety of industries, including petroleum refining, chemical process and pulp and paper mills. The plugs currently in use are typically in the shape of a truncated cone with a flow passage through the center, as shown in FIG. 1. While these plugs perform well, they suffer some disadvantages. Plug valves are manufactured in a wide range of sizes, typically from about 1/2" to about 36". For special applications, the valves are manufactured in even larger sizes. A steel valve plug for a 24" valve weighs about 5,300 pounds. The high weight of the larger plugs make them difficult to handle, both during the manufacturing process and after they are placed in service. The valves are typically opened and closed by lifting the plug from the valve body, rotating the plug, and re-seating it within the body. The weight of the plugs places a high demand on the equipment used to actuate the valve. Additionally, due to the varying thickness of the wall surrounding the flow channel, casting shrinkage problems occur during manufacturing. Also because of the thickness of the walls, the seating surface of the plug has no flexibility. Further, since any portion of the exterior surface of the plug may engage the valve body seat, the entire exterior surface of the plug must be precision machined to provide the tight tolerances required for efficient operation of the valve. Some applications, such as those involving high temperature corrosive steam and oil, require hard-surfacing of the seating surfaces on both the valve plug and the valve body. Hard-surfacing involves depositing a facing on the seating surfaces of the valve plug and the valve body, then precision machining the facing. The seating surfaces on the present plugs are not well-defined, therefore requiring hard-surfacing of a larger area of the plug surface to ensure that the seating surface is properly treated.